Coupling system



Aug. 8, 1933. HYLAND 1,921,526

COUPLING SYSTEM Filed March 25, 1929 3 Sheets-Sheet l ATTORNEY L. A.HYLAND COUPLING SYSTEM Aug. 8, 1933.

Filed March 26, 1929 3 Sheets-Sheet 2 INVENTOR.

ATTORNEY L. A. HYLAND COUPLING SYSTEM Aug. 8, 1933.

Filed March 26, 1929 v 5 Sheets-Sheet 3 Zr-ll 1N VEN TOR.

Qaw cem Q, a

ATTORNEY Patented Aug. 8, 1933- UNITED stares 1,921,526 v COUPLINGSYSTEM Lawrence A. Hyland, Washington, 1). 6., assignor to Wired Radio,Inc., New York, N. Y., a Corporation of Delaware Application lVlarch 26,1929. Serial N0. 350,052

2 Claims.

My invention relates broadly to coupling systems employed in electricalsignaling systems.

One of the objects of my invention is to provide a coupling systemadapted to control the 5 transfer of energy between different circuits.

Still another object of my invention is to provide an aperiodic couplingsystem adapted to control the transfer of high frequency energy betweena space radio energy. collecting system and a radio receiver. 1

Another object of my invention is to provide a coupling system adaptedto control the transfer of electrical energy between different circuitswithout materially altering the frequency characteristics of thecircuits.

A further object of my invention is to provide an improved couplingmeans adapted to control the transfer of energy between two circuitswhereby normal coupling is obtainable and adjustable coupling isobtainable by a common control.

Other and further objects of my invention reside in certain arrangementsof the constituent parts for elfecting the controlof energy betweendifferent circuits as set forth more fully in the specificationhereinafter following by reference to the accompanying drawings, inwhich:

Figures 1 and 2 show different operative characteristics of the couplingsystem of my inven-- tion; Fig. 3 is a schematic circuit diagram showingone application of the coupling system of my invention; Figs. 4, 5, 6,7, 8 and 9 are schematic circuit diagrams showing different applicationsof the control system of my invention and Figs. 10, 11 and 12 are front,side and rear elevations, respectively, of a preferred form of thecoupling unit employed in the coupling system of my invention. I

In signaling systems it is necessary to provide certain means forcoupling two or more circuits whereby electrical energy from'the oneistransferred to the other. It is often desirable and not infrequentlynecessary to control the transfer of such energy within certain limits.The ordinary control of such energy transfer is accomplished byadjusting thefre uency characteristics of one of the circuits to valuesother than the frequency characteristics of the other. This is in turnaccomplished by changing the inductive relation of inductances, changingthe value of the inductance or changing the value of the capacity.

In signaling systems where ordinary volume control means are included,it is nearly always the case that the volume control mechanism resultsin an overall decrease of received signal at all times. For instance, apotentiometer connected between antenna and ground by-passes a certainamount of energy which reduces the input to the grid of the first vacuumtube. The 6 system described in my invention, however, makes provisionforremoving from the circuit entirely the volume control mechanismwhenever maximum sensitivity is required.

Other methods include capacity coupling where an adjustable capacitybetween the two circuits controls the energy transfer or where theelectrical or magnetic properties of the material between the twocircuits is, changed, such as where the iron is substituted in an aircore transformer or, impedance. Each of the foregoing. methods hascertain disadvantages well known to those skilled in the art. Thecoupling system of my invention avoids many disadvantages of "othercoupling systems, as will appear from the description following. r Fig.1 is a schematic circuit diagram showing the coupling system of myinvention as employed to control thetransier of energy between twocircuits. A space radio energy collecting, system includes antenna 9 andground 10.. In ordinary practice antenna 9 and ground 10 are connecteddirectly to inductance 12. Inductance 12 may be the input of aradioreceiver 11, adapted to transfer energy to inductance 13Iby virtue oftheir inductive relation. Theelectro-magnetic field around inductancel2," threading through the axis. of the solenoid cuts the turns ofinductance 13. By rotating inductance 12 with respect to inductance 13the lines of force cutting the turns of inductance 13 will be reduced.The energy across opposite terminals of inductance 13 will accordinglybe reduced. Since the inductive relation between inductance 12 and13,.is thus changed, the frequency characteristics of the circuits arethereby changed. In the system of my invention. inductances 12 and 13are maintained in their normal inductive relation therefore eliminatingthe objectionable change in the frequency characteristics of thecircuits.

In high frequencies of the order of 15,000 kilocycles employed in spaceradio communication, minute changes in the frequency characteristics ofthe circuits are to be avoided. A coupling F control unit is employed inthe coupling system of'my invention which comprises resistor 1, contactarm 2, spring contact members 3'and 4, and insulating cam 5 positioned.on. shaft 6. One end of resistor 1 is connected to ground 10 and oneterminal of inductance 12. The other end of resistor 1 is connected tospring contact member 3. Contact arm 2 is positioned on shaft 6 and iselectrically connected to one terminal of inductance 12. Spring contactmember 4 is electrically connected to contact 8 and mechanicallyconnected ground 10 are connected directly to inductance 12 and thearrangement is similar to that gen-- erally employed wherein the antennaground connection is connected to the receiver.

In Fig. 2 of the accompanying drawings, antenna 9 is connected tocontact 8 and ground 10 is likewise connected to one end of resistor 1.In this arrangement, however, contact arm 2 has been moved alongresistor 1 and connects with a portion thereof. One end of resistor 1 isconnected to antenna 9'by means of the circuit established betweenspring contact members 3 and 4. The circuit established between members3 and L -is caused by virtueof the position of cam 5 whereby springcontact member 4 bears against the round portion of cam 5.

Cam 5 moves in common with the movement of contacting arm 2 and henceactuates spring con tact member 4 accordingly. The circuit, in thearrangement shown in Fig. 2, is from, antenna 9 through resistor 1 toground 10 with inductance 12 of receiver 11 connected to a pointonresistor 1 between the extreme ends thereof. The potential acrossinductance 12 of receiver, 11 is proportional to the resistance value ofresistor 1 between I the point upon which arm 2 rests and theconsupplied inductance 12 of receiver 11 increasescorrespondin 'ly; Theadjustment shown in Fig. 1 is that where the maximum potential is acrossinductance l2 and wherein resistor 1 in no way frequency amplifier 2c.employed as a high frequency amplifier is "shown influences theoperational characteristicsof the coupling between antenna 9, ground 10and re ceiver 11. In the adjustment shown in Fig. 2 the maximumpotential is not transferred to receiver 11, but only potential thevalue of which is determined by the position of contacting arm 2-withrespect to the resistance value of resistor 1 and the potential acrossresistor 1 in its. en tirety. Resistor 1 maybe constructed so as to benon-inductive. If wire wound, this may be accomplished by winding thewire double wherein one length neutralizes the other with respect toinductive reactance of such winding.-

Fig. 3 of the accompanying drawings shows one application of thecoupling system of my invention; Thermionic tubes 20, '21, 22 andare'adapted to operate as high'frequency 3,1'1'11311 fier, detector,and. audio frequency amplifiers; The schematic circuit dagram isintendedto represent merely a conventional d 'ign of radio receiving set such asemployed in the reception of high frequency modulated signaling energy;An tenna 9 and ground 10 are associated with inductance 19 comprisingthe input circuit of high The thermionic tube as that of the screen gridor shield anode of tube wherein the auxiliary electrode is supplied witha source of potential whereby the polarity of such electrode is positivewith respect may be of any suitable value whereby the frequencycharacteristics are substantially aperiodic when employed where thereceiver is adapted to receive signaling energy of very high frequencysuch as of the order of 15,000 kilocycles. Con"- pling unit 18 issimilar to that shown in detail the foregoing figures. In'such anarrangement signaling energy of great audibility is possible. When suchaudibility is too great coupling unit 18 is adjusted whereby theimpressed p0 tential across inductance 19 is reduced. Since inductance19 is substantially aperiodic to very high frequency signals it isobvious that reduc- I ing the input potential to thermionic tube 20 willaid in the selectivity since the response characteristics of the systemare thereby controlled. The aid in selectivityis not accomplished in themanner commonly employed wherein the frequency adjusting means isadjusted, but by changing the input potential of thermionic tube 20 byvirtue of the resistance of unit 18.

Where frequency adjusting means are used to'reduce volume, it is, ofcourse, true that the circuits are detuned with respect to the desiredsignal but of necessity placed in tune at some other frequency. Hence-ifan undesirable signal at the second frequency happens to be on the air,it will cause considerable interference.

Through the means of the present invention the signal is reduced inintensity but all tuning adjustments remain in their optimum positionfor the frequency desired and any interfering signal at some otherfrequency will be rejected as effectively for the low volume conditionas for the high volume condition. That is, while the selectivityis notimproved by the volume control itself, theuse of the volume controlmakes it possible to retain the maximum selectivity inherent insubsequent stages or circuits at all times whether on maximum or minimumvolume.

It is frequently the'casein extremely high frequency signaling systemsof the order of 15,000 kilocycles, that adistant stationcauses'interference witha nearby station or that the nearbystationcauses interference with reception of the signaling energy'fromthe more distant station. It is therefore desirable, without'in theleast changing the frequency characteristics, to reduce the couplingbetween antenna 9, ground is and the adjusting of unit 18 controls theenergy trans ferred to inductance 13 from inductance 1'7 without.altering the frequency characteristics of either inductance. This is adesirable feature in asn'iuch as the methods commonly employed whenadjusted tocontrol regenerationjusually also change the frequencycharacteristics of either the input or output circuits both.

Figs. 5 and 6 show the coupling system of my invention employed tocontrol the transfer of energy between high frequency circuits lowfrequency circuits respectively.

Fig. 5 shows a high frequency transformer comprising windings 24 and 25associated with couin the other arrangements shown, the resistor iscompletely disconnected from the inductance when desired. By moving thecontactor arm along the resistor the potential delivered atterminals Bis controlled. When it is desired to obtain maximum potential atterminals B the contactor arm is moved to theposition shown. When thearm is moved along the resistor the ends of the entire resistor areautomatically connected across the entire inductance. Fig. 6 shows thisarrangement as applied to an audio frequency transformer 28 whereinwinding 26 is the primary associated with a source at terminals A andwherein coupling control unit 18 is connected to secondary winding 27adapted to control the energy delivered at terminals B.

Fig. 7 shows still another application of the coupling control system ofmy invention wherein the transfer of energy between thermionic tubes 29and 30 is controlled by unit 18. Upon observation it will be noticedthat the arrangement shown employs what is generally referred to asimpedance coupling wherein impedance 31 is connected in the anodecircuit of thermionic tube 29. The resistor of unit 18 is connected inan arrangement similar to that shown in the foregoing figures whereinthe resistor is not connected across impedance 31 when maximum energyfrom source A is to be delivered to terminals 13. When the contactor armof unit 18 is moved along the resistor, the entire resistor isautomatically connected across the entire impedance. This preventschanging in any way the operational characteristics of thermionic tube29 as would be the case when the resistance is reduced or the impedancereduced to accomplish the control of the energy.

In the usual arrangement of impedance coupling the input wire, leadingto the control electrode of thermionic tube 30, is connected toimpedance or choke coil 31 at a point on the coil other than the end towhich the anode of thermionic tube 29 is connected. This point ofconnection should be chosen with great care to prevent blocking of theamplifier. By means of coupling control unit 18 this point for desiredoperation is easily determined. I

Figs. 8 and 9 show still another application of the coupling system ofmy invention. Fig; 8 is a schematic circuit diagram showing unit 18connected with telephone receivers 32 and a source of energy at thetermnals A, When unit 18 is adjusted in the position shown, telephonereceivers 32 are connected directly to terminals A,

the resistor of unit 18 being entirely out of the circuit. When unit 13is further adjusted the resistor in its entirety is connected inparallel ceivers 32 would be constant irrespective of continued movementof the contacting of unit 18. Under these circumstances the resistanceacross the terminals A is the same for all positions in which thecontact arm of unit 18 is in contact with the resistance element whilethe input would be variable according to the position of the contactarm. The arrangement shown in Fig. 9 is similar to the arrangement shownin Fig. 8,

. loud speaker 33 being substituted for telephone receivers 32 shown inFig. 8.

mounted on panel 40, shaft 6 extending there-*- through. Resistor 1 ispositioned on frame 36 and is here'shown as a circular bent stripcarrying turns of resistance wire. Contacting arm 2 is positioned onshaft 6 and movable therewith. Arm 2 is of suitable spring metal bearingagainst resistor 1. Spring contact member 4 is supported by frame 36 andpositioned to bear against cam 5. Cam 5 may be of suitable insulatingmaterial which is molded or otherwise positioned to the end ofshaftfi.Fig. 12 shows a rear View of the unit in its entirety. Referencecharacters correspond to those previously referred to. Spring contactmembers 3 and 4 are shown engaged as caused by the movement of cam 5.Lugs 35, 38 and 39 are provided for connection to the external circuits.7

Irealize that many modifications oiv the coup ling system of myinvention are possible. Many arrangements are possible modified inaccordance with the application intended. Resistor 1 may be ofimpregnated material or of any suitable form other than that shown. Thecoupling control between two circuits may be varied 1 from maximum atwhich point the resistance is not in the circuit to adjustments lessthan maximum where the resistance is connected across at least one ofthe circuits and remains constant across such circuit, all of whichadjustments and circuit connections areefiected by a single controlmeans.

It is to be clearly understood that the embodie ments of my inventionshall not be restricted by the foregoing specification or by theaccompanying drawings but only by such restrictions as are imposed bythe appended claims.

What I claim as new and desire to secure by Letters Patent of the UnitedStates is as follows:

1. In a coupling device for coupling two cir- 1 mote from said contactpoint, the other of said 4 circuits having its terminals respectivelyconnected to said switch member and the terminal of said resistanceelement remote from said coninsulated tact point, two adjacent contactmembers, one

of said contact members'being connected with the end of said resistancemember adjacent said contact point, the other of said contact membersbeing connected to said contact point, a cam member carrying saidrotatable switch member,

said cam member being adapted to engage one K point-and the end of saidresistance remotefrom.

said contact point, a circuit to be coupled connected to said switchmember and the end of said resistancemember remote from said contactpoint, and means actuated by the rotation of said switch .member forconnecting said contact point to the adjacent end of said resistanceelement when said switch'emember engages said resistance element and fordisconnecting said contact point from said resistance member when saidswitch member engages said contact point, whereby the coupling betweensaid circuits may be continuously varied over a considerable range andmay be abruptly varied in a limiting position.

LAWRENCE A. HYLAND; I

